When cleaning a buret in the laboratory, you should begin by coating the inside with which of the following substances?

• A. distilled water
• B. a small amount of the solution to be used in the titration
• C. acetone
• D. concentrated sulfuric acid

Answer: (B)

Verified step by step guidance

1. Understand the purpose of cleaning a buret: it is to ensure that the inside surface is free of contaminants and that the solution used in the titration will not be diluted or contaminated by residual water or other substances.
2. Recognize that if you rinse the buret with distilled water only, residual water droplets can dilute the titrant solution, leading to inaccurate concentration and volume measurements.
3. Know that rinsing the buret with a small amount of the titrant solution (the solution to be used in the titration) coats the inside surface with the exact solution you will use, preventing dilution and ensuring accuracy.
4. Avoid using acetone or concentrated sulfuric acid for rinsing the buret because these substances can damage the buret or interfere with the titration process.
5. Therefore, the correct procedure is to rinse the buret first with distilled water to clean it, then with a small amount of the titrant solution to coat the inside before filling it for the titration.